Interdisciplinary clinical research on the combined effects of substance abuse and HIV infection on the central nervous system (CNS) is of considerable relevance to public health initiatives. However, there are presently few laboratories conducting such research and (aside from ours) no current training programs dedicated to preparing the next generation of investigators in this critical area. In its first funding period or Ruth L Kirschstein National Research Service Award Institutional Training Grant (NRSA T32) entitled, Training in Research on Addictions in Interdisciplinary NeuroAIDS (TRAIN) has brought together a talented and culturally diverse cohort of pre- and post-doctoral trainees, an accomplished multidisciplinary team of mentors, an effective administrative structure, and a broad array of academic resources, with what is now a proven track record in preparing the Nation's next generation of academics to lead the field of substance abuse and neuroAIDS. The 9 students and fellows mentored during the current funding period have achieved remarkable productivity: In total, they have published nearly 60 manuscripts in the scientific literature (24 s first author) and have made over 70 presentations in scientific conferences (28 first authored); they also have successfully competed for 5 extramural and 3 intramural grants to further their research; and 3 have obtained new faculty or research scientist positions. Accordingly, we propose a renewal of TRAIN to build on these successes for the future of the field. Its aim is to prepare a steady state of three pre-doctoral and two post-doctoral trainees in clinical neuropsychology for multidisciplinary academic careers focused on the CNS effects of substance abuse and HIV infection, with a new theme on aging with these comorbid conditions. TRAIN emphasizes research training in three primary, interrelated CNS outcomes, which were selected for their scientific and